Rosatom is said to be eyeing a stake in Horizon, the nuclear joint venture put up for sale last month by RWE and E.ON. The move would be controversial, despite Russia's insistence that it has overhauled its nuclear technologies since the Chernobyl disaster.

Sergey Novikov, Rosatom's Director of Communications, told TheDaily Telegraph: "The British market is potentially attractive for Rosatom. Rosatom can give all guarantees that the construction of a NPP [nuclear power plant] in the UK will meet absolutely all international safety requirements and International Atomic Energy Agency standards."

Horizon planned to build new plants on Anglesey and at Oldbury but its backers, RWE and E.ON, withdrew amid financial difficulties in Germany.

A Department of Energy and Climate Change spokesman said: "The UK is open for business and actively welcomes inward investment to our energy sector.

"Any bid for UK energy assets is, and would be, subject to rigorous scrutiny through the established regulatory process."

Rosatom reportedly hired KPMG to examine possible purchases, while UK PR firms are said to be competing for a contract to improve Rosatom's international image. Rosatom is expanding overseas and has projects in India, Bulgaria, Iran and China.